Olav, it looks great. But, I do think it is too tall. As for anchoring, I would use both of the washers you sketched and machine screws that extend all the way through the body. You can clamp much better and it will never be inclined to move on you. You could also add some "texture" to the underside so that it grips the body. Not sure how you might want to. But, just something to help it sink in. One other thought... Will the short scale length have an effect on the intonation? I'm wondering if you might want to do a test with a fully adjustable bridge and your neck mounted to a 2x4 or something. This would give you a good idea of the angle you want on your "simple compensated" bridge.